[lbry] reject invalid claim names at mempool

blockchain/validate.go

@@ -228,8 +228,8 @@ func withinLevelBounds(reduction int64, lv int64) bool {
 }
 
 // CheckTransactionSanity performs some preliminary checks on a transaction to
-// ensure it is sane.  These checks are context free.
-func CheckTransactionSanity(tx *btcutil.Tx) error {
+// ensure it is sane.
+func CheckTransactionSanity(tx *btcutil.Tx, enforceSoftFork bool) error {
 	// A transaction must have at least one input.
 	msgTx := tx.MsgTx()
 	if len(msgTx.TxIn) == 0 {
@@ -288,15 +288,10 @@ func CheckTransactionSanity(tx *btcutil.Tx) error {
 				btcutil.MaxSatoshi)
 			return ruleError(ErrBadTxOutValue, str)
 		}
-		if txscript.ClaimScriptSize(txOut.PkScript) > txscript.MaxClaimScriptSize {
-			str := fmt.Sprintf("claimscript exceeds max size of %v",
-				txscript.MaxClaimScriptSize)
-			return ruleError(ErrBadTxOutValue, str)
-		}
-		if txscript.ClaimNameSize(txOut.PkScript) > txscript.MaxClaimNameSize {
-			str := fmt.Sprintf("claim name  exceeds max size of %v",
-				txscript.MaxClaimNameSize)
-			return ruleError(ErrBadTxOutValue, str)
+
+		err := txscript.AllClaimsAreSane(txOut.PkScript, enforceSoftFork)
+		if err != nil {
+			return ruleError(ErrBadTxOutValue, err.Error())
 		}
 	}
 
@@ -552,7 +547,7 @@ func checkBlockSanity(block *btcutil.Block, powLimit *big.Int, timeSource Median
 	// Do some preliminary checks on each transaction to ensure they are
 	// sane before continuing.
 	for _, tx := range transactions {
-		err := CheckTransactionSanity(tx)
+		err := CheckTransactionSanity(tx, false)
 		if err != nil {
 			return err
 		}

mempool/mempool.go

@@ -963,7 +963,7 @@ func (mp *TxPool) maybeAcceptTransaction(tx *btcutil.Tx, isNew, rateLimit, rejec
 	// Perform preliminary sanity checks on the transaction.  This makes
 	// use of blockchain which contains the invariant rules for what
 	// transactions are allowed into blocks.
-	err := blockchain.CheckTransactionSanity(tx)
+	err := blockchain.CheckTransactionSanity(tx, true)
 	if err != nil {
 		if cerr, ok := err.(blockchain.RuleError); ok {
 			return nil, nil, chainRuleError(cerr)

txscript/nameclaim.go

@@ -1,7 +1,9 @@
 package txscript
 
 import (
+	"bytes"
 	"fmt"
+	"unicode/utf8"
 
 	"github.com/btcsuite/btcd/wire"
 )
@@ -134,17 +136,8 @@ func StripClaimScriptPrefix(script []byte) []byte {
 	return script[cs.Size():]
 }
 
-// ClaimScriptSize returns size of the claim script minus the script pubkey part.
-func ClaimScriptSize(script []byte) int {
-	cs, err := DecodeClaimScript(script)
-	if err != nil {
-		return len(script)
-	}
-	return cs.Size()
-}
-
-// ClaimNameSize returns size of the name in a claim script or 0 if script is not a claimtrie transaction.
-func ClaimNameSize(script []byte) int {
+// claimNameSize returns size of the name in a claim script or 0 if script is not a claimtrie transaction.
+func claimNameSize(script []byte) int {
 	cs, err := DecodeClaimScript(script)
 	if err != nil {
 		return 0
@@ -156,8 +149,8 @@ func ClaimNameSize(script []byte) int {
 func CalcMinClaimTrieFee(tx *wire.MsgTx, minFeePerNameClaimChar int64) int64 {
 	var minFee int64
 	for _, txOut := range tx.TxOut {
-		// TODO: lbrycrd ignored transactions that weren't OP_CLAIMNAME
-		minFee += int64(ClaimNameSize(txOut.PkScript))
+		// TODO maybe: lbrycrd ignored transactions that weren't OP_CLAIMNAME
+		minFee += int64(claimNameSize(txOut.PkScript))
 	}
 	return minFee * minFeePerNameClaimChar
 }
@@ -200,3 +193,29 @@ func isUpdateClaim(pops []parsedOpcode) bool {
 		pops[4].opcode.value == OP_2DROP &&
 		pops[5].opcode.value == OP_2DROP
 }
+
+const illegalChars = "=&#:*$@%?/\x00"
+
+func AllClaimsAreSane(script []byte, enforceSoftFork bool) error {
+	cs, err := DecodeClaimScript(script)
+	if err != ErrNotClaimScript {
+		if err != nil {
+			return fmt.Errorf("invalid claim script: %s", err.Error())
+		}
+		if cs.Size() > MaxClaimScriptSize {
+			return fmt.Errorf("claimscript exceeds max size of %v", MaxClaimScriptSize)
+		}
+		if len(cs.Name()) > MaxClaimNameSize {
+			return fmt.Errorf("claim name exceeds max size of %v", MaxClaimNameSize)
+		}
+		if enforceSoftFork {
+			if !utf8.Valid(cs.Name()) {
+				return fmt.Errorf("claim name is not valid UTF-8")
+			}
+			if bytes.ContainsAny(cs.Name(), illegalChars) {
+				return fmt.Errorf("claim name has illegal chars; it should not contain any of these: %s", illegalChars)
+			}
+		}
+	}
+	return nil
+}

txscript/nameclaim_test.go

@@ -71,3 +71,17 @@ func TestCreationParseLoopSupport(t *testing.T) {
 	r.Equal(claimID, script.ClaimID())
 	r.Nil(script.Value())
 }
+
+func TestInvalidChars(t *testing.T) {
+	r := require.New(t)
+
+	script, err := ClaimNameScript("tester", "value")
+	r.NoError(err)
+	r.NoError(AllClaimsAreSane(script, true))
+
+	for i := range []byte(illegalChars) {
+		script, err := ClaimNameScript("a"+illegalChars[i:i+1], "value")
+		r.NoError(err)
+		r.Error(AllClaimsAreSane(script, true))
+	}
+}